Refrigerating apparatus



YJuly 5, 1932 L. s. KElLHoLTz l REFRIGERATING APPARATUS Filed Dec. 3l, 1923 3 Sheets-Sheet 2 l ily.; v

July 5 1932- L. s. KEILHoLTz 1,866,040

REFRIGERATING APPARATUS Filed Dec. 31,1923 s sheets-sheet s Il #lll/IIN llll 5l Z755 @my Patented July 5, 1932 UNITED STATES PATENT oFFlcE LESTER S. KEILHOLTZ, OF DAYTON, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS, T FRIGIDAIRE CORPORATION, A CORPORATION OF DELAWARE REFRIGERATING- APPARATUS Application led December 31, 1923. Serial No. 683,589.

This invention relates to the improvements in the construction of refrigerator cabinets especially those for mechanical refrigerators.

One object of this invention is to provide a simple quick and efficient method of assembling the cabinet.

Another object is to provide improvements in securing the'lieat insulating material in place whereby the outer surface of the inner metal linings of the cold compartments is absolutely protected from coming in Contact with warm outside air, and thus condensation of moisture on said outer surface is prevented.

Another object is to provide a water drain pipe for an upper cold compartment which does not pass through the insulated compartment below and hence provides a simpler construction.

Another object is to provide improvements in the air circulation system in the cold compartments.

Another object is to provide a door construction which causes the condensed water on the inner surface thereof to run down on the ioor of the compartment instead of onto other parts of the door and thence out at the door sill.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of embodiment of the present invention is clearly shown.

In the drawings:

Fig. l is a vertical section through a refrigerating cabinet embodying this invention but shows the refrigerating units in elevation.

Fig. 2 is a vertical section on line 2 2 of Fig. 1.

Fig. 3 is an enlarged vertical section through the door of the cooling compartment.

Fig. 4 is an elevation of the door along line 4-4 of Fig. 3, with parts broken away to show manner of securing in place the inner metal lining.

Fig. 5 shows on a greatly enlarged scale the construction of certain parts shown in Fig. 1.

Fig. 6 shows on an enlarged scale the construction of the central iiue shown in Fig. 1.

Figs. 7 to 10 inclusive show the method of constructing the cabinet.

Figs. 7 and 8 are front and side views respectively showing the upper and lower compartment linin s rigidly secured to a subfront or inner rame.

Fig. 9 is a section through the cabinet on line 9 9 of Fig. 1, showing one side wall of the cabinet removed to expose the construction of the insulating walls.

` Fig. l0 is a top view of the cabinet with the top removed to show the supporting beams for the cooling unit.

Throughout the several views like or similar reference characters refer to like or similar parts.

Numeral 20 designates the heat insulated upper cooling compartment containing the cooling unit 2l; 22 is the lower heat insulated food compartment, and 23 is the uninsulated bottom compartment containing the refrigerating machinery 24, which in the drawings has been illustrated as an electric motor driven SO2 compressor, condenser, and appurtenant devices. Both of the heat insulated compartments 20 and 22 are provided with sheet metal linings 25 and 26 respectively. These linings 25 and 26 are built up as separa-te unitary box like structures having an open front as best shown in Fig. 2. These linings are provided with flanges 27 around the edges of the open front to enable them to be rigidly secured to the front frame-work of the cabinet. A very important feature of this invention is the method and order of assembling the linings, the heat insulating walls, and the outer cabinet construction.

An inner wooden frame 30, such as clearly shown in Figs. 7 and 8 and which will hereinafter be termed the sub-front, is provided for supporting the two linings 25 and 26 in rigid relation during the rst steps of the assembly. The two separate box-like structures 25 and 26, with the iiangedholes 31 and 32 cut therein in their bottom and top walls respectively for the air circulation flues, are rst rigidly attached to the sub-front 30 by means of nails, screws, small metal clamps,

` be secured to the cross member of sub-front 30. The shortV metal flues 34 and 35 are next inserted in the registering holes 31 and 32 in the upper and lower linings and hammered into snug engagement with the flanges thereof. Molten hydrolene or other suitable material is next applied around the outside of the flues 34 and 35 to give an absolutely air tight sealed joint between the interior of the compartments and the space outside thereof.

The term ,hydrolene as herein used is known to the trade as indicating any suitable bituminous, asphalt or pitch-like material, such as certain bituminous compounds marketed and sold, which melt and liquefy upon the application of heat, and which remain in a semi-solid condition for an indefinite period when cold.

The heat insulation is next applied. First the narrow space between linings 25 and 26 is filled with a hot plastic compound consisting of a mixture of hydrolene and ground cork in suitable proportions and tamped in tightly all around the flue openings. A mixture consisting of one part by volume of hydrolene with ten parts by volume of ground cork has been found satisfactory, though of course other proportions may be used or paraffin may be substituted for the hydrolene in the mixture if desired. When the mixture cools it adheres to the metal linings and so does not fall or run out. The ive. outside surfaces of the two linings 25 and 26 forming a single unit is next covered with rigid sections of insulating material. Preferably material well known in the trade as cork board is used for this purpose. First there' is prepared a molten mixture of three parts by volume of hydrolene having a melting point around 180 F. with one art by volume of cork dust or finely groundkiork. This forms a compound which is stringy when stretched and which is of the proper consistency for the present purpose. The preferred method of using pound is to immerse a piece of cork board in the hot compound so as to cover one face of the edges therewith and then to place the cork board in its proper place onthe linings. The mixture described has suflicient body so that suiiicient quantities of it adhere to the cork board to fill up all depressions or spaces between the linings and cork board ordinarily due to the metal linings being slightly buckled or warped,` and at the same time the mixture has the right consistency to flow freely into this plastic comand fill these spaces. The edges of the cork board which are covered with the mixture come in contact with similarly covered ed es of adjacent pieces of cork board. Pre erably the bottom, sides, back, and top of the linings are covered with the cork board in the order named. If desired the cork dust may be omitted from the molten hydrolene. Also the hydrolene may be applied to the outer surface of the lining as well as to the inner surface of the cork board.

By this construction, it should be noted that the entire interior lining is sealed from the insulating material by a material having a high thermal capacity and at the same time a low heat conductivity for a purpose hereinafter more fully set forth.

After the linings of the unit shown in Figs. 7 and 8 is covered with the heat insulation walls the outer casing of the cabinet is built up thereabout. Preferably the order of assembling this outer casing is as follows: First the ready formed sides 50 of the casing are attached to the sub-front 30 by suitable means such as long wood screws. These screws preferably have their heads in the sub-front and extend angularly outwardly into the sides 5() whereby the screws will not be exposed from the outside of the finished cabinet. Next the ceiling 5l of the machinery compartment 23 is screwed or nailed into place. Then the bottom frame or machine base 52 is put in and rigidly secured to the two sides 50. While this base 52 preferably1 is open at its central portion (which opening is covered by the metal base plate 53 of the machinery unit 24) it is necessary to drill holes therethrough for the drain pipe 40 as well as for the cooling water lines (not shown) for the sulphur dioxide condenser. Next the horizontal member 54 which supports the weight of cooling unit 2l at the rear of the cabinet is secured firmly to the sides 50 near the top thereof. The two support beams 55 extend across the top from member 54 to the sub-front 30 and are suitably secured in slots 56 cut in 'said members, as clearly shown in Figs. l and 2. These slots 56 provide a clearance space between the beams 55 and the top 57 of the cabinet. The top-57 and back 58 of the cabinet are the last to be secured in place. The cabinet is then painted after which the units 2l and 24 with their operative interconnections are installed. The doors 60 and 6l for the compartments 20 and 22 respectively are finally attached and the removable cover plate 63 for the machinery compartment 23 secured in position.

One feature of this invention is the arrangement of the water drain pipe 40 so that it does not pass through the lower compartment 22 at all. Since the compartment 20 is maintained at a lower temperature than compartment l22 and since the cold air circulates freely between these compartments through the circulation flues the moisture in the air will be condensed out to such an extent in compartment 20 -that the air will be well above dew point when in compartment 22 and hence it is necessary to provide a drain ipe' for compartment 20 only. Pipe 40 eads downwardly and outwardly from a point substantially at the juncture of the side wall with the floor of lining 25 .and thus entirely clears the lower lining 26. This is oblviously a simple construction since the metal linings need be pierced and sealed at only one point. Preferably the lower portion of Eipe 40 is detachable at 41 immediately uner the partition 51.

The cold air circulation system and the construction of the flues is also a feature of this invention. The elongated section removable fiues 45 telescope over the short sections 35, as clearly shown in Fig. 5, and are thus easily removably secured in place. Thev flues 45 are provided at their upper end with deflectors 46 which prevent water and dirt from falling into the food compartment and which are so bent as to deflect the up-flowing air along the metal lining. The flow of air will then be upward adjacent the walls of both compartments and downward in the central portions thereof. By this means the transference of heat through the insulating walls will be lessened since the coldest air will not be in contact with the inner surfaces of the walls. The deflectors 46 are preferably of sheet metal 'and riveted or soldered to a down turned flange on the flues 45 'as clearly shown in the drawings.

Another feature of the invention is the construction of the door 60 to the cooling compartment (see Figs. 3 and 4). The outer wood panel is built up from a layer of preferably tongue and grooved boards at its center, which layer is covered with one or more layers 66 of veneering on each side. The relatively thick wood frame 67 for the insulating walls is screwed to the veneered panel from the inside of the door by the short screws 68 which are inserted at the -bottom of the holes 69 provided therefor in frame 67. The heat insulating material 70, inside the frame 67 is preferably cork board and is applied against the wood panel with a hydrolene mixture in the manner already described herein for the com artment walls. The inner metal lining 71 o the door is held in place by the pins or screws 72 at the sides (see Fig. 4) and the fianged wood strip 73 extending around the top and two sides of the door. At the lower edge the metal lining 71 is provided with a flange -7 5 bent inwardly and upwardly around a bead cut in the bottom'frame member 67 as clearly shown in Fig. 3. It will be clear that water condensed on the inner surface of linin 71 will run down and drip from the lower e ge rather than run `down onto .frame member 67. When the door is in closed position the lower edge 7 5 is vertically above the inclined sill slanting downward into the compartment 20 and thence the condensed water will flow down onto the floor of the compartment 2O and thence out at drain-.pipe 40. v

An important aspect of this cabinet construction is the use of the asphaltic or similar sealing material between the inner lining of the refrigerator and the insulating material. In actual use the inner refrigerator lining is, of course, maintained at a relatively low temperature by the cooling unit 21., There is therefore a tendency for moisture to collect on this lining by condensation of moisture from the warmer atlnosphere outside the refrigerator box. By completely sealing the cold surface, or, in other words, the inner 1ining, such condensation is entirely prevented and the life of the insulating material is prolonged indefinitely. At the same time, the lining is entirely surrounded by material having a high thermal capacity.

While the form of embodiment of the present invention as herein disclosed constitutes a preferred form, it is to be understood thatA other forms mightbe adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. A compound wall structure, comprising an inner wall, an outer wall, an interposed insulating layer adjacent to but spaced from at least one of said walls and providing space for a filling and a filling in said space, said filling being of a material adapt-ed for insertion therein in a substantially liquid state.

2. A compound wall structure comprising an inner wall, an outer wall, an interposed insulating slab of corklike material adjacent to at least one of said walls but providing space for a filling, and a filling in said space, said'filling being of a material adapted for insertion therein in a substantially liquid state.

3. A compound wall structure comprisino' an inner wall, an outer Wall, an interposed insulating layer adjacent to at least one of said walls and providing space for a filling and a filling in said space having adhesive properties and serving to unite the insulating layer and the adjacent wall, said filling being of a material adapted for insertion therein in a substantially liquid state.

4. A compound wall structure, comprisin an inner wall, an outer wall, an interposed insulating layer adjacent to at least one of said walls and providing space for a filling, and a filling semi-solid at normal temperatures in said space, said filling being of a material adapted for insertion therein in a substantially liquid state.

5. A compound wall structure, comprising a protective wall, an insulating layer adjacent to said wall and providing space for a filling, and a filling in said space, said filling 'lio side of the wall member, and a bituminous mass adhering to the coated surface of the wall member and interposed between the coated surface of the Wall member and the filler slab.

8. A mechanically cooled portable refrigerator having an insulated compartment, said compartment comprising an inner lining, an outer surrounding Wall, an interposed insulating layer adjacent to but spaced from at least one of said walls, and providing a space for afilling and a filling in said space, said filling being of a material adapted for insertion therein in a substantially liquid state.

9. A portable refrigerator cabinet having an inner cold surface an outer surface surrounding said cold surface, an interposed insulating layer adjacent to but spaced from at least one of said walls, and providing space anJ inner wall directly exposed to low temperatures on its inner side, an outer wall sur roun said inner wall and spaced therefrom, insulating material between said walls and spaced from said inner wall to rovide a s ace for a fillinganda fillinlg in sai space, sai filling compnsin an as altic material adapted to be inserte in sald space in substantially liquid form and having a low heat conductivity and a high thermal capacity and completely sealin the outer side of said metal wall against con ensation of moisture there- In testimony whereof I hereto aix my signature. l

LESTER S. KEILHOLTZ.

for a filling and a filling in said space, said filling adapted to be inserted. in liquid form and comprising an asphaltic material havin a low heat conductivity and a high therma capacity and completely sealing sa1d cold surface from said insulating material.

10. A portable mechanically cooled refrigerator having an insulated compartment, sald compartment comprising an inner metal wall directly exposed to low temperatures on its inner side, an outer Vwall surrounding said metal wall and spaced therefrom, insulating material between said walls, and s aced from the inner wall to provide space or a filling and a filling in said space, said filling comprising an asphaltic material adapted to be mserted in said space in substantially liquid form, and having a low heat conductivity and a high thermal capacity and completely sealing the ,outer side of saidl metal wall against condensation of moisture thereon.

11. A portable refrigerator including a compartment, a metal surface at least partially surrounding said compartment and adapted to be maintainedat a relatively low temperature, an outer wall spaced from said inner surface, insulating material between said wall and said surface and spaced from said surface to provide a space for a filling, an asphaltic material in said space, said asphalt completely sealing said cold surface from condensation of moisture on the outer surface of said cold surface.

12. A portable refrigerator including a compartment, said compartment comprising 

